This invention relates to a material handling attachment adapted to be mounted on a pair of lift arms of a vehicle such as a front-end loader, and more particularly to such an attachment which is capable of displacing a load of material within a greater range of travel than comparable prior art attachments.
In the prior art, there has been developed a forklift type of attachment adapted to be mounted on the lifting arms of a vehicle such as a conventional front-end loader. Typically, such attachment has consisted of a mounting frame pivotally mountable on the lift arms of a front-end loader and connectable to a pair of tilt cylinders of the front-end loader for tilting the mounting frame, and a pair of tines rigidly mounted on the mounting frame which are adapted to be inserted in clearances beneath a load to be lifted for lifting and relocating such loads. In the use of such an attachment, the front-end loader first is positioned before the load to be repositioned with the tines thereof disposed usually at ground level and in alignment of the clearances beneath the load, the machine is advanced to position the tines beneath the load, the lift arm cylinders are operated to lift the load on the tines, the machine is maneuvered to the desired location of the load, and the described procedure essentially is reversed to reposition the load at the desired location.
More recently, for the purpose of expanding the capability of such attachments, the tines thereof have been made vertically displaceable relative to the mounting frame. Typically, such attachments have consisted of a mounting frame pivotally mountable on a set of lift arms, a tine support frame mountable on the mounting frame and displaceable vertically relative to the mounting frame and a set of tines rigidly mounted on the vertically displaceable support frame. Examples of such attachments are disclosed in U.S. Pat. Nos. 3,070,244 to LeGrand H. Lull, 3,647,099 to Russell F. Carriere, 3,966,070 to John W. Barth and 4,657,471 to Akebumi Shinoda.
Although such improved forklift type attachments have been an improvement over prior art attachments in providing a greater range of travel of the tines, they have been found to be deficient in several respects. In particular, it has been found that the mounting and/or displaceable support frames of such attachments continue to obstruct the line of sight of the operator viewing the ends of the tines in attempting to align the tines with the clearances beneath a load to be lifted and to position the tines therein. In addition, the use of large and bulky displaceable, tine support frames has been found not only to reduce the payload of such attachments but to substantially increase manufacturing costs. It thus has been found to be desirable to provide an attachment of the type described having an extended range of travel of the tines thereof which eliminates such deficiencies. It has also been found to be desirable to provide an attachment having tines which can be actuated independently of each other.
Accordingly, it is the principal object of the present invention to provide an improved material handling attachment mountable on a pair of lift arms of a vehicle such as a front-end loader.
Another object of the present invention is to provide an improved material handling attachment mountable on a set of lift arms of a vehicle of the type having a set of tines insertable in clearances beneath a load to be lifted.
A further object of the present invention is to provide an improved forklift type attachment mountable on a set of lift arms of a front-end loader and the like, in which the tines of the attachment are displaceable vertically relative to a frame on which they are supported.
Another object of the present invention is to provide an improved forklift type of attachment mountable on a set of lift arms on a front-end loader and the like, in which the tines of the attachment are displaceable independent of each other.
A still further object of the present invention is to provide an improved forklift type attachment mountable on a set of lift arms of a front-end loader and the like, in which the line of sight of the operator with the free ends of the tines of the attachment is less obscured compared to comparable prior art attachments.
Another object of the present invention is to provide an improved forklift type attachment mountable on a set of lift arms of a front-end loader or the like, having a set of tines displaceable vertically relative to a mounting frame thereof, and providing a lesser weight than comparable prior art attachments, thus providing an increased payload of the attachment.
Another object of the present invention is to provide an improved forklift type attachment mountable on a set of lift arms of a front-end loader or the like, having a set of load supporting tines displaceable vertically relative to a support frame thereof, in which the manufacturing costs thereof are substantially reduced.
A still further object of the present invention is to provide an improved forklift type attachment mountable on a set of lift arms of a front-end loader and the like, and having a set of load supporting tines displaceable vertically relative to a support frame thereof, which is comparatively simple in design, comparatively inexpensive to manufacture and easy to maintain and service.
Other objects and advantages of the present invention will become more apparent to those persons having ordinary skill in the art to which the present invention pertains from the following description taken in conjunction with the accompanying drawings.